Some Comments on the Beta-Excited X-Ray Source

Abstract

AbstractThe potential of the beta-ray excited X-ray source was evaluated in the search for a small, low energy, planar source for gross apposition studies. Such a. source utilizes the familiar phenomena wherein target impingement by particulate radiation from certain pure beta emitters is utilized for the production o£ useful bremsstrahlung and characteristic X-radiation. Some of the favorable attributes of such a source are; simplicity of design and fabrication, diminutive size, stability, low cost, zero power consutnption and the gamut of synthetic radioisotopes with which they may be powered. This paper deals with the preliminary development of such a beta-excited source for application to apposition radiography as well as with the small, compound source-target.The design of such a source type is concerned with certain stimulating problems, some of which are; development of adequate photon intensity, reduction of excessive white radiation production, shielding for scattered and spurious radiation, target and source s elf-absorption, Simple illustrations of source-target geometries are reviewed both for compound and separate source-target design. Some resolution studies for the gross apposition source are shown, plus some exposures made with compound sources. The available synthetic isotopes are described and preliminary applications with P32 , Sr90, Y90 and Pm147 sources are outlined. The paper is divided into two portions; one, a brief review of theory and design; two, construction and results for the apposition and compound source.